A radioactive substance has a half-life of 3 days. If a mass of 1.55g of this substance is left after decaying for 15 days, determine the original value of the mass

A. 49.6g
B. 37.2g
C. 24.8g
D. 12.4g

Correct Answer: Option A

A. 49.6g

Explanation

1→1/2→1/4→1/8→1/16→1/32

1/32 =1.55g

1 = 1.55 x 32 =49.6g